Music21Loader

loader.score.Music21Loader(**kwargs)

Load symbolic scores using music21.

Returns ScoreStore with category-specific data. Uses recursive element parsing to extract: - Notes/Rests (with chord expansion) - Measures (structure) - Controls (dynamics, tempo, etc.) - Annotations (text)

All TTA timelines start at coordinate 0. When music21 reports negative quarter-beat offsets (anacrusis notes preceding the first full measure), this loader shifts every event coordinate so the earliest onset maps to 0.0. The magnitude of that shift is exposed via :attr:anacrusis_offset and stored in ScoreStore.metadata["anacrusis_offset"].

See PartituraLoader for the full rationale; both loaders apply the same convention so that score timelines built from either source are directly comparable and compatible with MatchfileLoader.

Attributes

Name	Description
anacrusis_offset	Quarter-beat shift applied to normalise anacrusis coordinates.